Statistical optimization of electrochemical oxidation of ethylene glycol using response surface methodology

Abstract

Large amounts of ethylene glycol (EG) based antifreeze liquids are daily discharge into the receiving waters. The chemical oxygen demand (COD) detected in most of the lakes and rivers close to the discharge points exceeded 100 000 mg O 2 /L. With such an amount, biological and chemical processes are inefficient to completely remove EG. In order to efficiently remove EG, electrochemical oxidation (ECO) of EG was carried out. Niobium Boron Doped Diamond (Nb/BDD) was used as anode whereas carbon felt was used as cathode. Different operating parameters including current intensity, treatment time, electrolyte concentration and pollutant concentration were tested. The application of 0.077A/cm 2 of current density during 120 min in the presence of 7.0 g/L of Na 2 SO 4 allowed 89.6 ± 0.2 % of COD removal with 490 mg O 2 /L of residual COD. This result was far below the legislation standard set by the province of Quebec that allows the discharge of 800 mg O 2 /L of COD. The efficiency of ECO process was attributed to both direct and indirect oxidation that generate strong oxidizing species (OH°, S 2 O 8 2-, H 2 O 2 , etc.) capable of oxidizing organic matters on the surface of the anode and in the bulk of the solution.

A Bibliometric and Visualized Overview for the Evolution of Process Safety and Environmental Protection

“…Subsequently, during the period between 2013 and 2017, the research emphasis turned to topics such as pollution management framework [ 148 ], analysis of isotherms and kinetics of adsorption [ 149 ], heavy metals risk assessment and removal [ 150 ], wastewater treatment (especially based on the advanced oxidation process (AOP) and electrocoagulation (EC)) [ 151 ], biodiesel processing and production [ 152 ], process safety framework and model [ 153 ], risk-based design [ 154 ], hazardous materials transportation safety [ 155 , 156 ], investigation and risk analysis of fire and explosion accidents (especially dust explosion) [ 154 , 157 ], etc. In terms of analysis/process methods, AOP [ 158 ], EC [ 159 ], photocatalysis degradation [ 160 ], activated carbon adsorption [ 161 ], biodegradation [ 162 ], catalytic pyrolysis [ 163 ], response surface methodology (RSM) [ 164 ], quantitative risk assessment (QRA) [ 165 , 166 ], multi-objective optimization [ 167 ], fuzzy FTA [ 168 ], numerical simulation [ 169 , 170 ], and Bayesian network (BN) [ 154 ], etc., were widely applied by scholars.…”

A comparative study on the mineralization of waste butyl acetate by electrochemical oxidation via persulphate/hypochlorite and silver (II) reagents using DSA® anodes: Statistical optimization by response surface methodology

“…In another work, we conducted mediated electrochemical conversion of low-value heavy fuel oils (HFOs) to valuable products. [14] The Sim-Dist results proved that by applying the electrochemical technique, the HFO was converted to light liquid fuels (10% gasoline and kerosene), 20% atmospheric gasoil, 40% vacuum gasoil, and 30% heavy residuals. [14] Treatment of mixed industrial wastewater was also carried out by MEO based on persulphate/hypochlorite ions using commercial Dimensionally Stable Anode (DSA) ® anodes (Ti/Ru 0.34 Ti 0.66 O 2 ) at pH 7.7 within 1 h electrolysis.…”

“…[14] The Sim-Dist results proved that by applying the electrochemical technique, the HFO was converted to light liquid fuels (10% gasoline and kerosene), 20% atmospheric gasoil, 40% vacuum gasoil, and 30% heavy residuals. [14] Treatment of mixed industrial wastewater was also carried out by MEO based on persulphate/hypochlorite ions using commercial Dimensionally Stable Anode (DSA) ® anodes (Ti/Ru 0.34 Ti 0.66 O 2 ) at pH 7.7 within 1 h electrolysis. [19] The results demonstrated COD and colour abatement efficiencies of 55% and 99.8%, respectively.…”

“…In fact, the oxidation of water molecules by these mediators, which is suggested to generate powerful OHÁ radicals, could occur in both mechanisms. [14] Typically, the electrochemical technique occurs at low temperatures, low voltages, and atmospheric pressure, hence it is known as an environmentally friendly technology. [15] In recent years, applications of electrochemical oxidation in organic destruction as well as surface modification of macromolecules (polymers) have been thoroughly investigated.…”

Artificial neural networks and genetic algorithms: An efficient modelling and optimization methodology for active chlorine production using the electrolysis process

“…[7] In empirical modelling, the structure of the data-fitting model should be specified a priori which makes it challenging as one needs to choose a suitable model structure among the many available ones, especially for non-linear processes. [8] Electrochemical processes for water and wastewater treatment are generally complicated non-linear systems and dependent on many factors such as the influent concentration of contaminants, [9] the applied current density and electrical potential, [10] the types of electrodes, [11] the electrolyte type and concentration, [12] and chemical interactions between contaminants. [13,14] It is thus difficult to use phenomenological or empirical models to model, simulate, and optimize the processes.…”